<?php
if(isset($_GET['action']))
        $action=$_GET['action'];
else    
        $action=null;

   switch($action){
        case "themdonvictdt":
            include("insertdonvi_ctdt.php");
            break;
        case "dsdonvictdt":
            include("donvi_ctdt.php");
            break;
        case "xoadonvictdt":
            include("deletedonvi_ctdt.php");
            break;
        case "suadonvictdt":
            include("suadonvi_ctdt.php");
            break;
        default:
            include("donvi_ctdt.php");
            break;
     }
?>